Fix trigger for ALTER TABLE SET ACCESS METHOD DEFAULT (#321)

1. `cmd->name` is empty (NULL) in the case of `ACCESS METHOD DEFAULT`,
so we should check for NULL before cmp.

2. Make trigger aware of the case when default AM is `tde_heap`

Fixes PG-1106

src/pg_tde_event_capture.c

@@ -137,11 +137,14 @@ pg_tde_ddl_command_start_capture(PG_FUNCTION_ARGS)
 		AlterTableStmt *stmt = (AlterTableStmt *) parsetree;
 		ListCell   *lcmd;
 
-		/* TODO: it might make sense to cehck rd_rel->relkind  */
 		foreach(lcmd, stmt->cmds)
-        	{
+		{
 			AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd);
-			if(cmd->subtype == AT_SetAccessMethod && strcmp(cmd->name, "tde_heap")==0) {
+			if (cmd->subtype == AT_SetAccessMethod && 
+				(cmd->name != NULL && strcmp(cmd->name, "tde_heap")==0) ||
+				(cmd->name == NULL && strcmp(default_table_access_method, "tde_heap") == 0)
+				)
+			{
 				tdeCurrentCreateEvent.encryptMode = true;
 				tdeCurrentCreateEvent.eventType = TDE_TABLE_CREATE_EVENT;
 				tdeCurrentCreateEvent.relation = stmt->relation;

t/008_tde_heap.pl

@@ -85,6 +85,15 @@ PGTDE::append_to_file($stdout);
 $stdout = $node->safe_psql('postgres', 'SELECT * FROM test_enc3 ORDER BY id ASC;', extra_params => ['-a']);
 PGTDE::append_to_file($stdout);
 
+$stdout = $node->safe_psql('postgres', 'CREATE TABLE test_enc4(id SERIAL,k VARCHAR(32),PRIMARY KEY (id)) USING heap;', extra_params => ['-a']);
+PGTDE::append_to_file($stdout);
+
+$stdout = $node->safe_psql('postgres', 'INSERT INTO test_enc4 (k) VALUES (\'foobar\'),(\'barfoo\');', extra_params => ['-a']);
+PGTDE::append_to_file($stdout);
+
+$stdout = $node->safe_psql('postgres', 'SET default_table_access_method = "tde_heap"; ALTER TABLE test_enc4 SET ACCESS METHOD DEFAULT;', extra_params => ['-a']);
+PGTDE::append_to_file($stdout);
+
 # Restart the server
 PGTDE::append_to_file("-- server restart");
 $rt_value = $node->stop();
@@ -140,6 +149,22 @@ PGTDE::append_to_file($strings);
 
 
 
+
+# Verify that we can't see the data in the file
+my $tablefile4 = $node->safe_psql('postgres', 'SHOW data_directory;');
+$tablefile4 .= '/';
+$tablefile4 .= $node->safe_psql('postgres', 'SELECT pg_relation_filepath(\'test_enc4\');');
+
+$strings = 'TABLEFILE4 FOUND: ';
+$strings .= `(ls  $tablefile4 >/dev/null && echo yes) || echo no`;
+PGTDE::append_to_file($strings);
+
+$strings = 'CONTAINS FOO (should be empty): ';
+$strings .= `strings $tablefile4 | grep foo`;
+PGTDE::append_to_file($strings);
+
+
+
 $stdout = $node->safe_psql('postgres', 'DROP TABLE test_enc;', extra_params => ['-a']);
 PGTDE::append_to_file($stdout);
 
@@ -149,6 +174,9 @@ PGTDE::append_to_file($stdout);
 $stdout = $node->safe_psql('postgres', 'DROP TABLE test_enc3;', extra_params => ['-a']);
 PGTDE::append_to_file($stdout);
 
+$stdout = $node->safe_psql('postgres', 'DROP TABLE test_enc4;', extra_params => ['-a']);
+PGTDE::append_to_file($stdout);
+
 # DROP EXTENSION
 $stdout = $node->safe_psql('postgres', 'DROP EXTENSION pg_tde;', extra_params => ['-a']);
 ok($cmdret == 0, "DROP PGTDE EXTENSION");

t/expected/008_tde_heap.out

@@ -17,6 +17,9 @@ INSERT INTO test_enc3 (k) VALUES ('foobar'),('barfoo');
 SELECT * FROM test_enc3 ORDER BY id ASC;
 1|foobar
 2|barfoo
+CREATE TABLE test_enc4(id SERIAL,k VARCHAR(32),PRIMARY KEY (id)) USING heap;
+INSERT INTO test_enc4 (k) VALUES ('foobar'),('barfoo');
+SET default_table_access_method = "tde_heap"; ALTER TABLE test_enc4 SET ACCESS METHOD DEFAULT;
 -- server restart
 SELECT * FROM test_enc ORDER BY id ASC;
 1|foobar
@@ -29,8 +32,12 @@ TABLEFILE2 FOUND: yes
 CONTAINS FOO (should be empty): 
 TABLEFILE3 FOUND: yes
 
+CONTAINS FOO (should be empty): 
+TABLEFILE4 FOUND: yes
+
 CONTAINS FOO (should be empty): 
 DROP TABLE test_enc;
 DROP TABLE test_enc2;
 DROP TABLE test_enc3;
+DROP TABLE test_enc4;
 DROP EXTENSION pg_tde;